Problem: $\dfrac{8}{5} - \dfrac{2}{10} = {?}$
Answer: $ = {\dfrac{8 \times 2}{5 \times 2}} - {\dfrac{2 \times 1}{10 \times 1}} $ $ = {\dfrac{16}{10}} - {\dfrac{2}{10}} $ $ = \dfrac{{16} - {2}}{10} $ $ = \dfrac{14}{10}$